This invention pertains to sheets for mattresses such as for beds, cribs or playpens and the like.
Conventional crib sheets comprise a single sheet or panel of fabric covering the top of the crib mattress. The single sheet is held on the mattress by elastic sheet corners that fit snugly on the corners of the mattress. As described in U.S. Pat. No. 6,067,677 to Reen et al., this design has significant drawbacks, notably that the sheet can be pulled off by an infant and the infant can become entangled amidst the unraveled sheet. The ""677 patent describes an attempt to encapsulate the crib mattress utilizing an elastic mattress entrance opening through the sheet and a Velcro flap that wraps over the opening and attaches to the bottom portion of the crib sheet. Another somewhat similar arrangement for a playpen mattress is shown in U.S. Pat. No. 5,642,540 which also has a flap that is secured to the bottom underside panel of the sheet. While these patents disclose various attempts to prevent unraveling of crib sheets, these patents have other drawbacks that have been discovered by the present inventor and which are remedied by the present invention.
The present invention is directed toward a sheet adapted to be form fitted on a mattress that overcomes drawbacks existing in the prior art while also preventing unraveling of the sheet. The sheet comprises generally rectangular top and bottom portions that are spaced apart generally parallel when form fitted on the mattress. A sidewall portion extends around the periphery of the top and bottom portions to define four sides. The sidewall portion is generally perpendicular between the top and bottom panels when form fitted on the mattress. A mattress opening extends laterally through the sidewall portion and is defined between lateral edges. The mattress opening extends along the length one side and at least partially along two adjacent sides. Fasteners on the lateral edges surrounding the mattress opening are operable to open and securely close the mattress opening.
It is an advantage according to one aspect of the present invention that the bed sheet is reversible and either the top side or the bottom side may be used on the top surface of the mattress. In either position, the mattress opening and fastening mechanism therefore is still hidden at the side or end of the mattress. The reversibility feature is particularly advantageous for messes made by infants, because the mattress can simply be turned over to expose the clean bottom side along the top. It will be appreciated that this is particularly helpful for example in the middle of the night when it would be arduous and time consuming to completely remove soiled mattress sheet and replace it with a clean mattress sheet.